Of all the games we heard news of, Super Mario 4 is easily the one we know the least about - after all, its existence hasn't even been confirmed by the Big N yet. If it's real - and since filing a domain for a sequel to a 24 year old game seems a little random otherwise, it's probably a good bet that it is - what could Super Mario 4 be? Could it be that new 2D Mario for 3DS company president Satoru Iwata mentioned at the last Nintendo investors meeting? Or something else entirely?

We'll no doubt have to wait a while for all the tasty details on this not-yet-confirmed but oh-god-please-be-real Mario game. In the meantime, take a look below at four possible routes Super Mario 4 might take.

A True Sequel

Retro revivals are all the rage, largely thanks to the success the Blue Bomber enjoyed with Mega Man 9 and Mega Man 10. These rocking Rockman titles were created to look and play just like an NES game, and returning to Mega's roots made for some seriously killer (and seriously nostalgic) gaming. It's possible Super Mario 4 could be something along the same lines - a true 8-bit sequel to the original Super Mario Bros. games (sprites, tiles and all).

More where this came from, please.

Before the comments section explodes: yes, we know Super Mario World was originally called Super Mario Bros. 4 in Japan - but that could perhaps explain why Nintendo is dropping the "Bros." branding for this one. Of course, this is all just speculation - but how amazing would it be to have a true follow-up to Super Mario Bros. 3, and to see the Mario developers let their creativity and imagination once again run wild within the limitations of the NES hardware? The game could even get the 3D Classics treatment, where you can choose to either play it with 3D on (which would pop out the layers in the foreground and sink back the layers in the background) or off (for a more traditional NES experience). It's a solid idea from where we're standing - so bring on the Kuribo's Shoe, Nintendo.

A 3D Platformer

Then again, it's possible Nintendo has the flawed idea that making a retro revival Mario game would be too much of a risk. Which would be a bummer. If that's the case, Super Mario 4 may just be a standard, side-scrolling platformer that's simply taking on the Super Mario branding - similar to what New Super Mario Bros. did, only minus the "New" (and the "Bros.").

It wouldn't be Mario's first foray into 3D.

The question this would raise is, why not just continue the New Super series? Perhaps it's because this new title will take things further than New Super Mario Bros. did - while, at the same time, paying more tribute to the original games. If this is the case, we might see familiar Power-Ups return, perhaps against the backdrop of full, gloriously 3D worlds scrolling by in the background with fully CG characters and enemies populating the foreground. It might even have the harsher difficulty and hidden surprises of the original games, as well as the multiplayer options of New Super Mario Bros. Wii.

A Modern Super Mario World

We already established that New Super Mario Bros. 4 already exists, as that's what Super Mario World was called in Japan. So perhaps Super Mario 4 is Nintendo's way of making a modern return to the World games. It's been about 17 years since Super Mario World 2: Yoshi's Island was released for the SNES (and no, in case you're wondering, that one wasn't called Super Mario Bros. 5 in Japan). It's about time for a proper revival, if you ask us.

Do it, Nintendo. DO IT.

If that's what Super Mario 4 turns out to be, you can expect the sophisticated platforming and unique personality World is known for. It would likely stick closer to the original game, with adult Mario riding Yoshi to victory, kicking shells in the air, and navigating branching pathways and secret levels. The game might even mix World gameplay with references and throwbacks to the first three Super Mario Bros. titles, all for a whole new adventure that compiles the best the Bros. have to offer.

Super Mario 4 Wii U

For all the 3DS buzz surrounding Super Mario 4, the truth is we don't know for sure that the game - if it does exist - isn't actually for Wii U. A first party launch title, perhaps? Nothing sells a Nintendo system like everyone's favorite plumber, so it certainly wouldn't be a crazy proposition (whether or not the thing showed up for launch or a bit later).

Will SM4 be Mario's Wii U debut?

We already saw a brief glimpse of what Mario might be like on Nintendo's new console at last year's E3 press conference. The demo was called New Super Mario Bros. Mii. As you'd probably guess, it was essentially HD New Super where you could play along with three other players (one person playing as Mario, the rest as their Mii character). We're not so sure about the Mii integration - we'd rather play as Luigi or Toad or Peach (or Geno, for crying out loud). However, a new Mario platformer for Wii U, especially one that pays homage to the franchise's roots, wouldn't be so bad.

These are just four ideas for what Super Mario 4 - if and hopefully when it's confirmed - might shape up to be. But who knows? Maybe it's a 3DS remake/compilation of Super Mario Bros. 1-3 and Super Mario World (that would be four games after all). Or maybe it's something completely unexpected. Regardless, as we wait for the details to start spilling, take a moment to vote in the poll below, then elaborate on your choice in the comments section. Have another hunch as to what Super Mario 4 might end up being? Let your voice be heard!

Audrey Drake is an Associate Editor of IGN.com and a proud member of the IGN Nintendo team. She is also a lifelong gamer, a frequent banisher of evil and a wielder of various legendary blades. You can follow her zany exploits on her IGN blog and Twitter. Game on!